The Mystery of the Missing Men

In 2013, we began looking into the mystery of Tost’s missing male snow leopards.

Lasya, one of the female snow leopards we’ve been tracking in Tost

We have been studying snow leopards in the Tost Mountains of Mongolia for over five years. There is no other snow leopard population in the wild that has been monitored for such a long period of time, which gives us the unique ability to look at population changes over time.

While preliminary data showed an adult population of 10-14 cats in our study site, in 2013 we started to see some vigorous underlying dynamics about how this population functions.

On the good side, the population has remained relatively stable over the past four years; indicating that the rate of immigration of new cats into the area, along with births, continues to offset the rates of mortality and snow leopard emigration out of our study site.

But digging deeper, there is something else brewing.

Over the last few years, the adult sex ratio appears to have changed considerably in favor of females. That means our big strong male snow leopards have been disappearing.

Is that normal or natural? Can this population survive with fewer males than females? Where do all the males go—and will they come back?

We had a tantalizing clue in fall 2013. Thanks to the support of our members, we were able to expand our study outwards and set out cameras in neighboring mountains to the north.

Aylagch, “the Traveller”

Who did we see but Agylach, a young male snow leopard that we had previously seen in Tost. Apparently, he felt the need to relocate, at least temporarily. Could these northern mountains be a piece of the ‘lost male’ puzzle?

It could be that males just don’t live as long as females due to high rates of competition and fighting. Or, like males of other big carnivores, they could be naturally more inclined to move and wander than females.

It could also be the case that males are more likely to attack livestock, making them more of a target for retribution killing by herders.

Right now these are all conjecture, but finding answers is paramount.

There could be threats facing males in particular, or wandering males could need greater protection of connected habitats. What’s certain is that we need to continue to monitor these snow leopards closely—and right now, we’re exploring even more nearby mountain chains.

Considering that throughout most of snow leopard range, even basic population estimates are still lacking, we have to admit we feel a little giddy (and spoiled) being able to learn so much, delve so deep, and make such truly incredible progress towards better understanding Mongolia’s cats.

Thank you for not only making this long-term study a reality, but enabling it to grow. In science, ‘surprises’ are usually the start of great achievement, and we are excited to see what answers we unlock next.